Synchronizing arrangement



y 1932- A. KAROLUS 1,856,076

SYNCHRONI ZING ARRANGEMENT Filed Nov 28, 1927 AMQMWR INVENTOR AUGU5T KARDLUS fj g/ Qdm ORNEY Patented May 3, 1932 UNIT D STATES PATENT AUGUST KAROLUS,'OF LEIPZIG, GERMANY, .ASSIGNOR TO RADIO CORPORATION OF AMERICA, A CORPORATION OF DELAWARE SYNCHRONIZING Application filed November 28, 1927, Serial No.

The present invention is concerned with an arrangement for synchronizing moving mechanisms for picture transmission or other purposes serving as a means of intelligence transmission. It more particularly relates to the case in which, in transmitter and receiver, synchronization and its maintenance is effected by the aid of time tappers priorly tuned or synchronized with each other, but

which are independent of each other during the picture transmission process itself.

For the same purpose, according to the prior art, oscillating tuning forks of like frequency have been used. These tuning forks,

in conjunction with suitable amplifier arrangements, furnished synchronizing alternating currents which were employed for the purpose of driving the mobile transmission devices by the aid of synchronous motors.

One disadvantage associated with these schemes has been the necessity of extensive amplification of the energy delivered by the tuning forlr until the same was large enough to furnish the requisite driving power.

The present invention obviates the disadvantages and drawbacks above named by providing suitable means to supply the main driving power at both the transmitting and receiving ends of the system. This is accom plished through the use of synchronous main motors roughly adjusted to the proper speed. From the shaft of the synchronous motors, or of a driving or gear part connected therewith, are supplementary or auxiliary synchronous motors to which alternating current energy produced by the vibrating tuning fork is fed. This energy supply to the auxiliary motor serves as a corrective energy only and furnishes but a small part of the whole driving energy. On account of the fact that the amplifier is called upon only to furnish a. part of the whole driving energy, no such high amplification is required and the supply thereof is insured by simpler means, while the danger of reactions in the form of forced oscillations (entraining) of the tuning fork frequency by that of the synchronous motor is more effectively precluded. As a matter of fact, it has been found that, if the total driving power of the transmitter or receiver ARRANGEMENT 236,063, and in Germany December 14, 1926.

apparatus amounts to around watts, only from 3 to 5 watts are needed in the shape of synchronizing alternating current energy.

One embodiment of the basic idea of the invention is shown by way of example in the accompanying drawing which forms a partof my disclosure and represents an arrangement suitable for use at both the transmitting and the receiving stations. Referring now to the drawing 1 are the vibrating tuning forks which serve at both the transmitting and the receiving ends, independently of each other, as time tappers to insure the synchronous condition. This tuning fork l is kept either at suhiciently constant temperature so as to maize its frequency at equately constant, or else it is made from special materials or is composed or assembled of special materials of a l? 1d in which the influence of thermal expansion and variation of elasticity in the presence of temperature fluctuations is compensated for as far as feasible, for instance, by reason of the fact that the coefiicient of expansion and the thermo-elastic coefficient are of the same sign, as has been disclosed by my copending application, Serial No. 235,- 761, files November 525, 192?. The tuning fork oscillates in conjunction with a regeneratively coupled amplifier of small, but constant, amplitude, the size of which is governed by the degree of back-coupling and the amplification factor of thermionic tube 3. For this purpose, tuning fork 1 by means of induction coi 2 acts upon the grid of tube 3, the plate circuit of which contains the reaction coil t, which maintains the constant oscillation of the fork 1. In order that as little reaction possible is caused by the synchronousmotor, operated atthe end of the output of the cascade amplifier 6, upon the tuning fork frequency, it is desired to couple the amplifier stages, which are assumed to be within the cascade amplifier 6, independently of the oscillator tube 3. This may be accomplished by connecting the input of the cascade 9 amplifier 6 to a separate and distinct induction coil 5 instead of connecting the amplifier input to the plate circuit of the tube 3. The alternating current energy induced in coil 5 when fork 1 oscillates is then amplified to the required watt value and thereupon supplied to the synchronizing motor which furnishes the part of the energy required to insure synchronous state. The simplest plan is to locate the synchronizing motor upon the shaft of the main motor 12, which may, for instance, be of the direct current shuntwound type although any other form of motor may be used, if desired. By the aid of rheostat 13, motor 12 is adjusted roughly to the proper speed. Upon the motor shaft 11 there is mounted atoothed wheel 10 built up from sheet packets, and the teeth of said wheel 10 are passed close to the magnet coils of the electromagnet system 7, 8 and 9. To the winding 9 there is supplied a constant exciting direct current and upon the latter there is superposed the amplified alternating current flowing in the windings 7 and 8 and having the frequency of the tuning fork.

Synchronous running of the shaft 11 with relation to the frequency of 1 can be checked up by the aid of glow-discharge lamp 14; which is supplied with the same frequency as 7 and 8. In the light of the lamp 14, the teeth of 10 seem to be stationary as long as synchronism prevails. Instead of the tootl wheel siren La Cour wheel), also any other kind of synchronous motor may be employed. Instead of a tuning fork, also any other mechanical oscillator can be used in connection with this invention.

Having now described my invention what I claim is:

1. A system for supplying energy to a work circuit or the like which includes a mechanical vibrator of constant frequency, a regeneratively coupled thermionic means for driving said mechanical vibrator, an amplifying eans, a separate means for inducing energy only of a frequency corresponding to the actual motion of said vibrator into said am plifier for amplifying the same, and means for supplying the output energy of said amplifier to the work circuit.

2. A system for supplying constant frequency energy to a load circuit or the like comprising a tuning fork of, constant frequency, a regeneratively connected exciter means for said fork, a one-way repeater circuit, independent energy pickup means adjacent said fork for inducing alternating current of a frequency corresponding to the actual vibrational frequency of said tuning fork into said amplifier, a load circuit connected with the output of said amplifier, means for applying said amplified energy to said load circuit, and means provided by said repeater and said independent energy pick-up for preventing reaction of said load circuit upon said tuning fork.

3. In a system for supplying constant frequency energy to a load circuit or the like, a tuning fork of substantially constant frequency, a regeneratively coupled vacuum tube amplifier for driving said fork, said regeneratively coupled amplifier haVingJthe energy pick-up coils thereof so arated y one tine of thedriven tuning for i, an energy pick-up coil adjacent the other tine of said tuning fork and separated from the other of said pick-up coils by the tines of said fork for generating electrical energy of a frequency corresponding to the actual vibrational frequency of the said tuning fork, and an amplifier for amplifying the generated electrical energy and means for supplying the amplified energy to the load circuit.

AUGUST KAROLUS. 

